The invention relates generally to power-driven conveyors and, more particularly, to modular conveyor belts constructed of a series of rows of belt modules split into multiple pieces and connected together by hinge pins.
Conventional modular conveyor belts and chains are constructed of modular links, or belt modules, arranged end to end and often side by side in belt rows. The modules typically extend from a top article-engaging surface to a bottom drive surface through their thickness. Spaced-apart hinge eyes extending from each end of the modules include aligned openings. The hinge eyes along one end of a row of a modules are interleaved with the hinge eyes along one end of an adjacent row. Pivot rods, or hinge pins, journalled in the aligned openings of interleaved hinge eyes, connect adjacent rows together end to end to form a conveyor belt capable of articulating about a drive sprocket or drum at the hinge formed by the interleaved hinge eyes between adjacent belt rows.
Although each belt row may include a single module defining the width of the belt, often each row includes a number of modules arranged side by side with a seam between them. Usually these belt modules composing the belt are arranged in a bricklay pattern to avoid a continuous longitudinal seam running the length of the belt. Such continuous seams would significantly decrease the beam strength of the belt. But, even in bricklayed modular belts, the seams in each row decrease the beam strength of the row. Furthermore, as the connecting hinge pins grow, the belt width can change because the modules have freedom to slide laterally and separate from each other at the seams. Besides varying the width of the belt, this separation can cause trip edges for products, pinch points for fingers, or gaps into which small conveyed products can fall or get caught.
Although most belt modules are made out of a homogenous material, such as metal or plastic, other belt modules are made of more than one material. For example, some belt modules include a resilient high-friction material molded, bonded, or otherwise attached to a slick low-friction plastic base. Belts made of these modules are useful, for example, in conveying articles up inclines and down declines. But complex molding techniques or messy secondary manufacturing steps are required to make the attachment.
To satisfy other applications, belt modules are often designed with moving parts that interact with conveyed products. Examples include belts with rollers for low backline pressure or for product indexing or offloading. Once again special manufacturing or molding steps are necessary to install these moving parts. In the case of some modular plastic roller-top belts, rollers are mounted on a metal axle that extends through support stanchions spaced apart across the module. The module is manufactured by carefully molding the module and its stanchions around the axle and rollers. When the molding is complete, the axle is held permanently in the stanchions. If a roller or stanchion is damaged, the module has to be removed from the belt and replaced. Repair is not possible.
Thus, in view of these shortcomings, there is a need for a conveyor belt module that may include a variety of accessories, even movable parts, and that is easy to manufacture and to repair in the field. There is also a need for a modular conveyor belt that exhibits even greater beam strength than a conventional bricklaid belt.
These needs and others are satisfied by a conveyor belt module and a modular conveyor belt constructed of these modules embodying features of the invention. In one version of the invention, the conveyor belt module includes a base piece with a first set of hinge eyes along a first end and a second set of hinge eyes along an opposite second end. A complementary piece also has first and second sets of hinge eyes along its first and second ends. The complementary piece mates with the base piece to form a conveyor belt module whose first sets of hinge eyes are aligned along a first axis and whose second sets of hinge eyes are aligned along a second axis. In various versions, the base and complementary pieces are substantially identical in structure or have the same number of hinge eyes along each end. In other versions, the module is reversible. Other versions include a component, such as a roller or an axle, that can be installed in or removed from the module when the base and complementary pieces are unmated, but is retained in place when the pieces are mated. The base piece can include a driving surface, and the complementary piece, article-engaging structure. The base piece and the complementary piece, in yet other versions, may be made of different materials.
In another version, the belt module is a split module with first and second sets of hinge eyes at opposite first and second ends of the module. The module is split into complementary pieces, preferably a first piece and a second piece. Each of the pieces, whether two or more, includes at least a portion of the hinge eyes. In another version, the module is split along confronting planar faces of each of the complementary pieces. In another version, the second piece, which includes article-engaging structure, stacks on the first piece, which serves as a module base, to form the module.
In still another version of split module, the module includes a module body with first and second sets of hinge eyes along opposite first and second ends of the module body. The module body includes a first piece and a second piece arranged in a stack to form the module body. In yet another version, the hinge eyes of each set formed by the first piece alternate with those of the second piece. In another version, the module also includes a roller assembly, such as a roller ball or a spherical or cylindrical roller with axle. The module body has an opening shared between the first piece and the second piece to accommodate the roller assembly. Retention structure at the periphery of the opening retains the roller assembly in place between the first and second pieces. In one version of this, the roller assembly includes a roller with an axle through the roller. The retention structure is in the form of indentations oppositely located across the opening to receive and retain the ends of the axle sandwiched between the first and second pieces with the roller free to rotate in the opening.
A modular conveyor belt embodying features of the invention can be made of any of the foregoing belt modules by arranging a plurality of the modules end to end with the first set of hinge eyes of a module interleaved and aligned with the second set of hinge eyes of an adjacent module and by pivotably connecting adjacent modules with hinge pins through the interleaved sets of hinge eyes.
Another version of modular conveyor belt comprises a series of rows of belt module pieces. Each row includes first and second sets of hinge eyes along opposite first and second ends of the row. Each row also includes a group of first module pieces arranged side by side in the row and forming at least some of the first and second hinge eyes. Each row further includes a complementary group of second module pieces arranged across the row and forming other of the hinge eyes. The complementary group mates with the first group of pieces to form the belt row. The rows are then arranged end to end with the first set of hinge eyes of a row interleaved with the second set of hinge eyes of an adjacent row and pivotably connected together into a conveyor belt by hinge pins through the interleaved hinge eyes. In another version of this belt, the complementary group of second module pieces is stacked on the group of first module pieces. In yet another version, at least one of the second module pieces mates with portions of two side-by-side first module pieces. In another version, seams formed between adjacent first module pieces are offset laterally across the row from seams formed between second module pieces to avoid seams through the thickness of the row and hence increase beam strength.
In another conveyor belt version, the belt is made up of a bottom layer of belt module pieces and a top layer of belt module pieces. The pieces in each layer have hinge eyes at opposite ends and are arranged end to end and side to side in a bricklay pattern with seams between adjacent side-by-side module pieces. The top layer lies on the bottom layer. Hinge pins extend through the hinge eyes of the top and bottom layers to connect them together in a conveyor belt.
In another version of split belt module, the module extends from a first end to an opposite second end and from a top side forming a generally flat conveying surface to a bottom side through the module""s thickness. The split module comprises a first piece forming a majority of the bottom side and a second piece forming a majority of the top side. The first and second pieces mate to form the belt module. In another version, the belt module includes another component, such as a roller and an axle for the roller. The second piece includes support structure extending from the top side to support the roller on the axle. The first piece includes retention structure to retain the axle in place on the support structure when the pieces are mated. This makes for a roller-top belt module whose rollers or axles can be replaced by unmating the first and second pieces.
A method for making a belt module having features of the invention include: forming a first belt module with hinge eyes at opposite ends; forming a second belt module with hinge eyes at opposite ends; mating the first and second belt module pieces with their hinge eyes aligned; and connecting the pieces together with hinge pins through the aligned hinge eyes. In a further method, a belt module with a component can be made by further installing the component on the first belt module piece before mating the two pieces.
Thus, the invention provides belt modules, belts constructed from modules like these, and methods for making belt modules with advantages such as versatile modules that can accommodate complex, even movable, components and yet are not difficult to manufacture and belts without through-seams that would decrease beam strength.